I have a 88 civic EF, 4 door sedan Lx, stock engine, recently the car has been idling around 2000 Rpms on a cold start, and sometimes goes all the way up to 2500.. What could possibly be causing that, and could that be causing my burning oil/black smog? If not what are some simple things that I could take a look at, it also had a timing belt change by a guy I knew, so maybe the timing isn't correct? Anything helps' thank you!

 

As far as I know all Hondas iddle at 2-3k on cold.
It's called cold idle. To make the car warm up fast.

Burning oil will be worn rings, valves, etc etc.